Work vehicles

Abstract

To restrain an internal combustion engine from consuming fuel and to restrain amount of emission of exhaust gas in a work vehicle.SOLUTION: A work vehicle comprises an internal combustion engine (E) which drives wheels (3), first electric motors (124R, 124L) which drive the wheels (3) when electric power is supplied, a dynamo-electric generator (102) which generates electric power by rotation of the driven wheels (3), a second electric motor (129) which drives a work machine (18) and a power storage part (126) which is capable of storing electric power generated by the dynamo-electric generator (102) and supplies the electric power to the second electric motor (129) when the work machine (18) is operated and at the same time supplies the electric power when driving the wheels (3) by the first electric motors (124R, 124L).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a work vehicle such as a rice transplanter or a tractor. [Background technology]

[0002] In work vehicles such as rice transplanters and tractors, which are so-called hybrid vehicles equipped with an internal combustion engine (7) and a generator-electric motor (12), a configuration is known in which power is transmitted to a rotary tiller (6) by an output shaft (7a) of the internal combustion engine (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-186110 A ("0018") Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional configuration in which the running wheels and working equipment are driven by an engine, as in the technology described in Patent Document 1, the load and output of the engine increase depending on the state of the field and the type of work being done, which tends to increase fuel consumption and exhaust gas emissions, creating a significant burden on the environment.

[0005] The present invention has as its technical object to reduce fuel consumption and exhaust gas emissions of an internal combustion engine (engine) in a work vehicle compared to conventional configurations. [Means for solving the problem]

[0006] The above-mentioned problems of the present invention are solved by the following means. The invention described in claim 1 is a vehicle comprising: a traveling vehicle body (1a) having wheels (3); an internal combustion engine (E) that burns fuel to generate power for driving the wheels (3); and first electric motors (124R, 124L) that generate power for driving the wheels (3) when supplied with electric power. Driving the internal combustion engine (E) a generator (102) capable of generating electricity based on the above, a work implement (18) provided on the traveling vehicle body (1a) and performing work on a field, a second electric motor (129) for driving the work implement (18), and a power storage unit (126) capable of storing the electric power generated by the generator (102), the power storage unit (126) supplying electric power to the second electric motor (129) when the work implement (18) is operating and supplying electric power to the first electric motors (124R, 124L) when the wheels (3) are driven by the first electric motors (124R, 124L). the generator (102) functioning as a third electric motor (102) that generates power for driving the wheels (3) when power is supplied; and a control unit (300) that drives the wheels (3) by the internal combustion engine (E), the first electric motors (124R, 124L), and the third electric motor (102) when the amount of electricity stored in the electricity storage unit (126) reaches a predetermined first threshold (Wa), and the control unit (300) drives the wheels (3) with the third electric motor (102) and the internal combustion engine (E) when the amount of electricity stored (W1) in the electricity storage unit (126) reaches a third threshold (Wc) that is smaller than the second threshold (Wb), drives the wheels (3) with the first electric motor (124R, 124L) and the internal combustion engine (E), and drives the wheels (3) with the internal combustion engine (E) when the amount of electricity stored (W1) in the electricity storage unit (126) does not reach the third threshold (Wc); The work vehicle is characterized by being equipped with:

[0007] Claim 2 The invention described in (1) is characterized in that the control unit (300) causes the generator (102) to generate electricity and store it in the electricity storage unit (126) when the amount of electricity stored (W1) in the electricity storage unit (126) does not reach the second threshold (Wb). Claim 1 It is a work vehicle described in

[0008] Claim 3 The invention described in is a work vehicle described in claim 1, characterized in that when the rotation speed of the internal combustion engine (E) reaches a predetermined rotation speed, the power generation load of the generator (102) is increased.

[0009] Claim 4 The invention described in is a work vehicle as described in claim 1, characterized in that it comprises an electric current-carrying unit (401) that is in contact with an electric powered overhead line (403) that is arranged across a field (402) and is capable of conducting electricity with the overhead line (403), and a power storage unit (126) that is capable of storing electricity from the overhead line (403) via the electric current-carrying unit (401).

[0010] Claim 5The invention described in (4) is characterized in that the overhead wire (403) is supported on one of a plurality of supports (404) provided in the farm field (402). 5. The work vehicle according to claim 4, wherein the overhead line (403) is According to the travel route of the work vehicle The support (404) Unmanned aerial vehicle (406) It will be rebuilt by Characterized by Claim 4 It is a work vehicle described in [Effects of the Invention]

[0011] According to the invention of claim 1, the electric power generated by the generator (102) is stored in the power storage unit (126), and when the work implement (18) is operating, the electric power is supplied from the power storage unit (126) to the second electric motor (129), and when the first electric motors (124R, 124L) are driving the wheels (3), the electric power is supplied from the power storage unit (126) to the first electric motors (124R, 124L). As a result, it is possible to reduce fuel consumption and exhaust gas emissions of the internal combustion engine (E) in the work vehicle (1) compared to a conventional configuration in which the work implement (18) and the wheels (3) are driven by the internal combustion engine (E).

[0012] Also, claim 1 According to the described invention, when the amount of electricity stored (W1) in the electricity storage unit (126) reaches the first threshold value (Wa), the wheels (3) are driven by the internal combustion engine (E), the first electric motors (124R, 124L), and the third electric motor (102). This reduces the load on the internal combustion engine (E) compared to when the wheels (3) are driven by the internal combustion engine (E) alone, thereby reducing the fuel consumption and exhaust gas emissions of the internal combustion engine (E).

[0013] Furthermore, claim 1According to the described invention, when the amount of electricity stored (W1) in the electricity storage unit (126) reaches the second threshold (Wb), the wheels (3) are driven by the third electric motor (102) and the internal combustion engine (E), thereby reducing the decrease in the amount of electricity stored (W1) compared to when the first electric motors (124R, 124L) are also used. Furthermore, when the amount of electricity stored (W1) reaches the third threshold (Wc), the wheels (3) are driven by the first electric motors (124R, 124L) and the internal combustion engine (E), thereby reducing the load on the internal combustion engine (E) compared to when the wheels (3) are driven by the internal combustion engine (E) alone. Furthermore, when the amount of electricity stored (W1) does not reach the third threshold (Wc), the wheels (3) are driven by the internal combustion engine (E), thereby reducing the decrease in the amount of electricity stored (W1) compared to when the first electric motors (124R, 124L) are used.

[0014] Claim 2 According to the described invention, Claim 1 In addition to the effects of the described invention, generating electricity by the generator (102) when the stored electricity amount (W1) does not reach the second threshold (Wb) promotes recovery of the stored electricity amount (W1) compared to when no electricity is generated.

[0015] Claim 3 According to the described invention, in addition to the effect of the invention of claim 1, it is easier to keep the rotation speed of the internal combustion engine (E) within the predetermined rotation speed, and damage to the internal combustion engine (E) is suppressed, compared to when the power generation load of the generator (102) is not increased when the rotation speed of the internal combustion engine (E) reaches the predetermined rotation speed.

[0016] Claim 4 According to the described invention, in addition to the effect of the invention of claim 1, electricity can be stored in the electricity storage unit (126) from the overhead line (403) through the current-carrying unit (401).

[0017] Claim 5 According to the described invention, Claim 4 In addition to the effects of the invention described above, by using an unmanned aerial vehicle (406) to change the overhead line (403) according to the route of the work vehicle (1), there is no need to lay the overhead line (403), and the cost of laying the overhead line (403) is reduced. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is an explanatory diagram of a tractor as an example of a work vehicle according to an embodiment, and is an explanatory diagram of a state in which a work implement is lowered to a height at which work can be performed. [Figure 2] FIG. 2 is an explanatory diagram of a tractor as an example of a work vehicle according to an embodiment, with the work implement in a raised position. [Figure 3] FIG. 3 is an explanatory diagram of the engine of the work vehicle according to the embodiment. [Figure 4] 4A and 4B are explanatory diagrams of the belt tension adjusting mechanism of the embodiment, in which FIG. 4A is a side view and FIG. 4B is a top view. [Figure 5] 5A and 5B are explanatory diagrams of other embodiments, in which FIG. 5A is an explanatory diagram of another embodiment of the embodiment shown in FIG. 4, and FIG. 5B is an explanatory diagram of yet another embodiment. [Figure 6] 6A and 6B are explanatory diagrams of a modified example of the embodiment shown in FIG. 5A, where FIG. 6A is an explanatory diagram of the case where there is one tension roller, and FIG. 6B is an explanatory diagram of the case where there are two tension rollers. [Figure 7] FIG. 7 is a functional block diagram of the work vehicle according to the embodiment. [Figure 8] FIG. 8 is a functional block diagram of the control unit according to the embodiment. [Figure 9] FIG. 9 is an explanatory diagram of another embodiment of the work vehicle of the present invention. [Figure 10] FIG. 10 is an explanatory diagram of a form in which the overhead line is switched. [Figure 11] FIG. 11 is an explanatory diagram of the case where materials are transported between a work vehicle and an unmanned aerial vehicle. [Figure 12] FIG. 12 is a perspective view of a diesel engine according to another embodiment. [Figure 13] FIG. 13 is an explanatory diagram of a state in which the harness stay is removed from the state of FIG. [Figure 14] FIG. 14 is an explanatory diagram of the harness stay. [Figure 15] FIG. 15 is an explanatory diagram of the state in which the DPF and resonator have been removed from the state shown in FIG. [Figure 16] Figure 16 is an explanatory diagram of the resonator fixing stay, where Figure 16(A) is an oblique view of the resonator fixing stay, Figure 16(B) is a side view of the stay, and Figure 16(C) is an explanatory diagram of the state in which a coupler has been assembled from the state in Figure 16(B). [Figure 17] Figure 17 is an explanatory diagram of the resonator, where Figure 17(A) is an oblique view, Figure 17(B) is a view from the direction of arrow XVIIB in Figure 17(A), Figure 17(C) is a view from the direction of arrow XVIIC in Figure 17(A), and Figure 17(D) is a view from the direction of arrow XVIID in Figure 17(A). [Figure 18] Figure 18 is a cross-sectional view of the resonator in Figure 17, where Figure 18(A) is a cross-sectional view taken along line XVIIIA-XVIIIA in Figure 17(B), Figure 18(B) is a cross-sectional view taken along line XVIIIB-XVIIIB in Figure 17(C), Figure 18(C) is a cross-sectional view taken along line XVIIIC-XVIIIC in Figure 17(D), and Figure 18(D) is a cross-sectional view taken along line XVIIID-XVIIID in Figure 17(D). [Figure 19] 19A and 19B are explanatory diagrams of an oil filler cap for engine oil according to an embodiment, where FIG. 19A is an explanatory diagram for when the internal engine pressure is low, and FIG. 19B is an explanatory diagram for when the internal engine pressure is high. DETAILED DESCRIPTION OF THE INVENTION

[0019] FIG. 1 is an explanatory diagram of a tractor as an example of a work vehicle according to an embodiment, and is an explanatory diagram of a state in which a work implement is lowered to a height at which work can be performed. FIG. 2 is an explanatory diagram of a tractor as an example of a work vehicle according to an embodiment, with the work implement in a raised position. 1 and 2, a tiller tractor 1 as an example of a work vehicle of the present invention is equipped with front wheels 2, 2 and rear wheels 3, 3 as an example of wheels at the front and rear of a traveling body 1a, and is configured so that the rotational power of an engine (an example of an internal combustion engine) E mounted in an engine room 4 at the front of the traveling body is appropriately reduced by a speed change device in a transmission case 5 and transmitted to the front wheels 2, 2 and the rear wheels 3, 3. The engine room 4 is configured to be covered by a hood 6. A work implement such as a tiller 18 for tilling the ground (field) behind the tractor 1 is attached to the rear of the body of the tractor 1, and power is transmitted to drive the work implement through a rear PTO shaft 21. In this specification, the left and right sides of the tractor 1 when viewed in the forward direction are referred to as the left and right sides, respectively, and the forward direction is referred to as the front side, and the backward direction is referred to as the rear side.

[0020] A cabin 7 is supported on the upper part of the traveling vehicle body 1a. Inside the cabin 7, a driver's seat 8 is disposed above the transmission case 5, and a steering wheel 10, a parking brake (not shown), and the like are disposed in front of the driver's seat 8. Also disposed in front of the driver's seat 8 are a display panel for a speedometer (not shown), various operation switches (not shown), and the like. Disposed below and in front of the driver's seat 8 are travel operating devices such as a brake pedal 12 and an accelerator pedal 13 having a forward pedal and a reverse pedal.

[0021] In Figure 1, a hydraulic cylinder case 14 is provided above the rear of the transmission case 5, and lift arms 15, 15 are pivotally mounted on both the left and right sides of this hydraulic cylinder case 14. Lift rods 17, 17 are interposed and connected between the lift arms 15, 15 and lower links 16, 16, and a cultivator 18, an example of a working machine, is connected to the rear of the lower links 16, 16.

[0022] When hydraulic oil is supplied to the hydraulic cylinder 14a housed in the hydraulic cylinder case 14, the lift arms 15, 15 are rotated upward, and the work machine (cultivator) 18 is raised via the lift rod 17, lower link 16, etc. Conversely, when the hydraulic oil in the hydraulic cylinder 14a is discharged into the transmission case 5, which also serves as a hydraulic tank, the lift arms 15, 15 are lowered. In addition, the work implements attached to the rear of the traveling body 1a, i.e., the work implements to which drive is transmitted from the rear PTO shaft 21, are not limited to rotary tillage devices for agricultural work, but also include work implements such as plows, seed sowing machines, seedling transplanters, fertilizer spreaders, and pesticide spreaders.

[0023] FIG. 3 is an explanatory diagram of the engine of the work vehicle according to the embodiment. In Fig. 3, engine E of the embodiment has a crankshaft 101 disposed at the lower end thereof as a transmission shaft and as an output shaft from an engine body 100. An ISG (Integrated Starter Generator) motor 102, which is an example of a generator and an example of a third electric motor, is supported diagonally above the right of the crankshaft 101. An ISG belt 103 is stretched between a pulley 102a of the ISG motor 102 and a crank pulley 101a of the crankshaft 101. Rotation is transmitted between the shaft 101 and the rotor. When energized, the ISG motor 102 generates power to function as a starter (starting device, starting motor) for the engine E and to assist in the rotation of the crankshaft 101, and can also function as an alternator (power generating device) that generates electricity as the crankshaft 101 rotates.

[0024] A water pipe 104 through which coolant for cooling the engine body flows is disposed in the engine E. A water pump 106 for circulating the coolant in the water pipe 104 is disposed above and to the left of the ISG motor 102. A pump drive motor 107 is disposed below and to the left of the water pump 106. A pump belt 108 is stretched between a pulley 107a of the pump drive motor 107 and a pulley 106a of the water pump 106, and power from the pump drive motor 107 is transmitted to the water pump 106. A hydraulic hydroshaft 109 is disposed coaxially with the output shaft of the pump drive motor 107. An electromagnetic clutch (not shown) is disposed between the pump drive motor 107 and the hydroshaft 109, and the pump drive motor 107 can switch between driving and non-driving the hydroshaft 109 depending on whether the electromagnetic clutch is turned on or off.

[0025] 4A and 4B are explanatory diagrams of the belt tension adjusting mechanism of the embodiment, in which FIG. 4A is a side view and FIG. 4B is a top view. When the rotation speed is high, the belts 103 and 108 are desirably tensioned because weak tension can easily cause slippage on the pulleys 101a, 102a, 106a, and 107a. On the other hand, when the rotation speed is low, excessive tension can shorten the lifespan of the belts 103 and 108. In response to this, it is desirable to provide a tension adjustment mechanism 111 for any or all of the pulleys 101a, 102a, 106a, and 107a, as shown in Figure 4. The tension adjustment mechanism 111 has a guide roller 113 that is movable along an annular (ring-shaped) guide groove 112 formed at the bottom inside the pulleys 101a, 102a, 106a, and 107a. One end of a link 114 is connected to the guide roller 113. The link 114 is configured to be rotatable around a fulcrum 114a. A tension roller 116 that contacts the outer surfaces of the belts 103 and 108 is supported on the other end of the link 114.

[0026] When the pulleys 101a, 102a, 106a, and 107a are not rotating, the guide roller 113 is positioned downward in the direction of gravity within the guide groove 112 due to its own weight and the reaction force that the tension roller 116 receives from the belts 103 and 108. When the pulleys 101a, 102a, 106a, and 107a rotate, the guide roller 113 moves upward in response to the rotation of the pulleys 101a, 102a, 106a, and 107a with which it is in contact. When the guide roller 113 moves upward, the tension roller 116 presses the belts 103 and 108 in the thickness direction via the link 114, increasing the tension. Here, the height to which the guide roller 113 moves upward increases as the force accompanying the rotation of the pulleys 101a, 102a, 106a, and 107a increases. Therefore, the higher the rotation speed of pulleys 101a, 102a, 106a, and 107a, the higher the height of guide roller 113 becomes, and the amount by which tension roller 116 presses belts 103 and 108 increases, increasing tension. 4, the tension of the belts 103 and 108 is adjusted according to the rotation speed of the pulleys 101a, 102a, 106a, and 107a, and the higher the rotation speed, the stronger the tension of the belts 103 and 108. Therefore, it is possible to increase the tension at high rotation speeds and decrease the tension at low rotation speeds, thereby suppressing slippage at high rotation speeds and also suppressing a decrease in the lifespan of the belts 103 and 108.

[0027] 5A and 5B are explanatory diagrams of other embodiments, in which FIG. 5A is an explanatory diagram of another embodiment of the embodiment shown in FIG. 4, and FIG. 5B is an explanatory diagram of yet another embodiment. 4, in a configuration in which the tension roller 116 is directly supported by the link 114, the tension roller 116 is prone to fluttering due to fluctuations in engine rotation and fluttering of the belts 103 and 108. In response to this, as shown in FIG. 5(A), it is possible to suppress the effects of fluttering by interposing a spring 117, which is an example of an elastic member, between the link 114 and the tension roller 116.

[0028] 6A and 6B are explanatory diagrams of a modified example of the embodiment shown in FIG. 5A, where FIG. 6A is an explanatory diagram of the case where there is one tension roller, and FIG. 6B is an explanatory diagram of the case where there are two tension rollers. In the configuration shown in FIG. 5A, in which a single spring 117 supports the tension roller 116, the tension roller 116 pushes the belts 103 and 108 in the thickness direction. However, when the belts 103 and 108 are rotating at high speeds, the tension roller 116 is likely to be pushed in the belt feed direction as the belts 103 and 108 rotate. If the tension roller 116 is pushed in the belt feed direction, the tension of the belts 103 and 108 does not increase, and the desired tension may not be achieved. In response to this, as shown in FIG. 6A, by using a configuration in which two springs 117a and 117b are angled to push the tension roller 116, when the tension roller 116 is pushed in the belt feed direction, one of the springs 117a and 117b contracts and the other expands, and the springs easily return to their original positions due to their elastic restoring force. This makes it easier to achieve the desired tension.

[0029] Furthermore, in the configuration shown in FIG. 5(A) in which the tension roller 116 is supported by a single spring 117, resonance may occur depending on the length of the belts 103 and 108 and the center-to-center distance between the pulleys 101a, 102a, 106a, and 107a, resulting in significant fluctuation and fluttering of the belts 103 and 108. If the position of the tension roller 116 coincides with a position where the amplitude of the flutter is large, the tension roller 116 may be unable to press the belts 103 and 108, making it difficult to obtain the desired tension. To address this issue, as shown in FIG. 6(B), by arranging the tension rollers 116a and 116b at different positions along the feed direction of the belts 103 and 108, even if one of the tension rollers 116a and 116b coincides with a position where the amplitude is large and the other cannot press the belts 103 and 108, the other can still press the belts 103 and 108, making it easier to obtain the desired tension. In particular, by changing the spring constants of the two springs 117a and 117b, it is expected that the effect of reducing fluctuations in rotation and natural vibrations (resonance) will be enhanced.

[0030] Alternatively, instead of tension adjustment mechanism 111, a tension adjustment mechanism 111' shown in Figure 5(B) can be used. In tension adjustment mechanism 111', an arm 118 supporting tension roller 116' is pushed by a spring 117, and the arm 118 can also be pushed by the hydraulic pressure of engine oil. Taking advantage of the fact that hydraulic pressure increases as the rotation speed of engine E increases, tension adjustment mechanism 111' can also adjust the tension to an appropriate level according to the rotation speed of engine E.

[0031] FIG. 7 is a functional block diagram of the work vehicle according to the embodiment. In FIG. 7, the power of a crankshaft 101 of an engine E is transmitted to an HST (Hydraulic Static Transmission) 121, which is an example of a transmission. The rotation, the speed of which is changed by the HST 121, is input to a front gear case 122. The power input to the front gear case 122 is transmitted to left and right front wheels 2, 2. The power input to the front gear case 122 is also transmitted to a left rear wheel gear case 123L and a right rear wheel gear case 123R. Each rear wheel gear case 123R, 123L is configured to be able to transmit power from a traction motor 124R, 124L, which is an example of a first electric motor, respectively. The output of each rear wheel gear case 123R, 123L is transmitted to the left and right rear wheels 3, 3, respectively. In the tractor 1 of this embodiment, in order to deal with the difference between the inner and outer wheels during turning, the left and right rear wheels 3, 3 are driven independently so that the rotation speed of the wheel on the outside of the turn is higher.

[0032] In the tractor 1 of the embodiment, a configuration in which the traction motors 124R, 124L are provided corresponding to the left and right rear wheels 3, 3 has been exemplified, but the present invention is not limited to this. A configuration in which one motor drives both rear wheels 3, 3 is also applicable. However, when using the same motor capacity, providing separate traction motors 124R, 124L on the left and right has the advantage of being able to drive the rear wheels 3, 3 more powerfully, and when the torque of the rear wheels 3, 3 is to be the same, providing separate traction motors 124R, 124L allows the use of smaller motors, which also has cost benefits.

[0033] The ISG motor 102 is electrically connected to a high-voltage battery 126 and a low-voltage battery 127, which are examples of a power storage unit. Therefore, when the ISG motor 102 is used in a power generation mode, the batteries 126, 127 can be charged and stored with the generated electricity, and when the ISG motor 102 is used in a driving mode, power can be supplied from the high-voltage battery 126. In this embodiment, the low-voltage battery 127 supplies power to the pump drive motor 107 and electrical devices such as lighting, a display panel, etc. A DC-DC converter 128, which is an example of a transformer, is connected between the low-voltage battery 127 and the high-voltage battery 126, and is configured to enable interchange of power between the low-voltage battery 127 and the high-voltage battery 126.

[0034] The high-voltage battery 126 in this embodiment is electrically connected to the travel motors 124R, 124L and can supply electric power when the travel motors 124R, 124L are in use. When supplied with electric power, the travel motors 124R, 124L generate power to drive the rear wheels 3, 3. The high-voltage battery 126 is also electrically connected to a work implement motor 129, which is an example of a second electric motor, and can supply electric power when the work implement motor 129 is in use. When activated, the work implement motor 129 generates power to rotate the rear PTO shaft 21, thereby operating the tiller 18, which is an example of a work implement.

[0035] (Explanation of the control unit) FIG. 8 is a functional block diagram of the control unit according to the embodiment. In the block diagram of FIG. 8, elements that are not related to the description of the embodiment of the present invention are not shown or described.

[0036] (Explanation of the tractor control unit) The tractor 1 of the embodiment has a control unit 300 that controls each function. The control unit 300 has an input / output interface I / O that performs input and output of signals with the outside. The control unit 300 also has a read-only memory (ROM) that stores programs and information for performing necessary processing. The control unit 300 also has a random access memory (RAM) for temporarily storing necessary data. The control unit 300 also has a central processing unit (CPU) that performs processing according to the programs stored in the ROM or the like. Therefore, the control unit 300 of the embodiment is configured with a small information processing device, a so-called microcomputer. Therefore, the control unit 300 can realize various functions by executing programs stored in the ROM or the like.

[0037] The control unit 300 receives signals from a remaining amount sensor SN1, a rotation speed sensor SN2, and various other sensors (not shown) and signal input elements such as input buttons. The remaining amount sensor SN1 detects the remaining amount of electricity stored in the high voltage battery 126. The rotation speed sensor SN2 detects the rotation speed of the engine E.

[0038] In addition, the control unit 300 can send control signals to the ISG motor 102, the travel motors 124R, 124L, the HST 121, the work machine motor 129, etc., as examples of controlled elements, to control the travel of the tractor 1 and the operation and stopping of the tiller 18.

[0039] In FIG. 8, the control unit 300 according to the embodiment has the following functional means (program modules). The remaining amount determination means 301 determines the remaining amount of electricity in the high-voltage battery 126 based on the detection result of the remaining amount sensor SN1. In the remaining amount determination means 301 of the embodiment, when the battery remaining amount W1 of the high-voltage battery 126 reaches the high remaining amount value Wa as an example of the first threshold value (when W1≧Wa), it is determined that the battery remaining amount W1 of the high-voltage battery 126 is sufficient. Also, when the battery remaining amount W1 does not reach the high remaining amount value Wa and reaches the medium remaining amount value Wb as an example of the second threshold value (when Wb≦W1<Wa), it is determined that the battery remaining amount W1 of the high-voltage battery 126 is medium. Further, when the battery remaining amount W1 does not reach the medium remaining amount value Wb and reaches the low remaining amount value Wc as an example of the third threshold value (when Wc≦W1<Wb), it is determined that the battery remaining amount W1 of the high-voltage battery 126 is low. Also, when the battery remaining amount W1 does not reach the low remaining amount value Wc (when W1<Wc), it is determined that the battery remaining amount W1 of the high-voltage battery 126 is almost none.

[0040] Note that the values of each threshold Wa~Wc can be appropriately set according to the design, specifications, etc. As an example, it is possible to preset the high remaining amount value Wa = 80%, the medium remaining amount value Wb = 50%, and the low remaining amount value Wc = 20%. Each threshold Wa~Wc can be a fixed value, or it can also be made changeable by an operator through button input or the like.

[0041] The rotation speed determination means 302 determines whether the rotation speed of the engine E is high based on the detection result of the rotation speed sensor SN2. The rotation speed determination means 302 of the embodiment determines that the engine E is in a high rotation state when the rotation speed R1 of the engine E reaches the predetermined high rotation determination value Ra.

[0042] The traveling mode setting means 303 sets the operations (traveling modes) of the engine E and the motors 102 and 124 for each traveling based on the remaining amount of the high-voltage battery 126 when the tractor 1 is traveling. In the embodiment, when the remaining amount of the high-voltage battery 126 is sufficient (when W1≥Wa), the traveling mode setting means 303 sets the first traveling mode in which the wheels 2 and 3 are driven by the engine E, the ISG motor 102, and the traveling motors 124R and 124L. When the remaining amount of the high-voltage battery 126 is medium (when Wb≤W1<Wa), the traveling mode setting means 303 sets the second traveling mode in which the wheels 2 and 3 are driven by the engine E and the ISG motor 102. When the remaining amount of the high-voltage battery 126 is low (when Wc≤W1<Wb), the traveling mode setting means 303 sets the third traveling mode in which the wheels 2 and 3 are driven by the engine E and the traveling motors 124R and 124L. When the remaining amount of the high-voltage battery 126 is almost none (when W1<Wc), the traveling mode setting means 303 sets the fourth traveling mode in which the wheels 2 and 3 are driven by the engine E.

[0043] Therefore, in the embodiment, in the first traveling mode and the second traveling mode, the ISG motor 102 functions as a traveling motor, and in the third traveling mode and the fourth traveling mode, the ISG motor 102 functions as a generator to charge the high-voltage battery 126. In addition, in the embodiment, in the second traveling mode, all the wheels 2 and 3 benefit from the drive of the ISG motor 102, but in the third traveling mode, only the rear wheels 3 and 3 benefit from the drive of the traveling motors 124R and 124L. Therefore, the second traveling mode can drive more powerfully than the third traveling mode.

[0044] The load setting means 304 sets the load when the ISG motor 102 is made to function as a generator based on the rotation speed of the engine E. When the rotation speed of the engine E is determined to be in a high rotation state, the load setting means 304 sets the power generation load to a high load state. For example, when the speed of the tractor 1 increases due to its own weight while traveling downhill and the rotation speed of the engine E increases, the ISG motor 102 is made to function as a generator and the electrical resistance (load) during power generation is increased (the resistance value of a variable resistor, not shown, is increased), thereby causing the ISG motor 102 to function as a brake, so to speak, to decelerate and suppress the rotation speed of the engine E.

[0045] In the tractor 1 of the embodiment having the above configuration, when operating the tiller 18, the power of the engine E is not used as in the conventional configuration, but the tiller 18 is operated by the work implement motor 129 powered by the high-voltage battery 126. Therefore, compared to the conventional configuration in which the engine drives the PTO shaft, the load on the engine E is reduced, making it possible to suppress fuel consumption by the engine E and exhaust gas emissions. Furthermore, when the remaining charge of the high-voltage battery 126 is sufficient, the tractor 1 travels in the first travel mode. That is, the tractor travels in a state in which it is power-assisted not only by the engine E but also by the ISG motor 102 and the travel motors 124R, 124L. This reduces the load on the engine E, and reduces fuel consumption and exhaust gas emissions.

[0046] Furthermore, when the remaining charge of the high-voltage battery 126 is medium, the tractor 1 travels in the second travel mode. That is, the tractor travels with power assistance not only from the engine E but also from the ISG motor 102. Therefore, compared to when there is no power assistance, the load on the engine E is reduced, fuel and exhaust gas are suppressed, and, compared to the first travel mode in which the travel motors 124R, 124L are also driven, there is no power consumption for the travel motors 124R, 124L, and the decrease in the remaining charge of the high-voltage battery 126 is also suppressed. Furthermore, when the remaining charge of the high-voltage battery 126 is low, the tractor 1 travels in a third travel mode. That is, the tractor travels with power assistance not only from the engine E but also from the travel motors 124R and 124L. Therefore, the load on the engine E is reduced compared to when power assistance is not provided, reducing fuel and exhaust gas emissions, and, compared to the first and second travel modes in which the ISG motor 102 is used for travel, power generation by the ISG motor 102 also promotes recovery of the remaining charge of the high-voltage battery 126.

[0047] Furthermore, when the remaining charge of the high-voltage battery 126 is almost zero, the tractor 1 runs in the fourth running mode. That is, the tractor 1 runs on only the engine E. Therefore, the tractor 1 runs without consuming power from the traveling motors 124R, 124L and with the ISG motor 102 generating power, which also helps restore the remaining charge of the high-voltage battery 126. Furthermore, in the tractor 1 of this embodiment, when the engine E is in a high rotation speed state, the power generation load of the ISG motor 102 as a generator is increased. Therefore, for example, even if the speed of the tractor 1 increases due to its own weight while traveling downhill, or if the engine E over-rotates due to excessive engine oil, the ISG motor 102 can also function as a brake to suppress the rotation speed of the engine E. This prevents damage to the engine E, decelerates the tractor 1, and prevents accidents.

[0048] FIG. 9 is an explanatory diagram of another embodiment of the work vehicle of the present invention. In the tractor 1 of the embodiment, as shown in Fig. 9, a pantograph 401 as an example of a current-carrying unit can be provided so that power can be supplied from an external source. In Fig. 9, the pantograph 401 can be installed on the upper surface of the cabin 7, and power can be supplied by contact with an overhead line 403 arranged across a field 402. By supplying power from the overhead line 403 via the pantograph 401, it is possible to charge the batteries 126, 127. This makes it easier to travel in the first traveling mode and makes it easier to suppress a decrease in the remaining charge of the high-voltage battery 126 even when the tiller 18 is operating. Furthermore, by configuring the tractor 1 to be able to supply power from an external source, the capacity of the batteries 126, 127 can be reduced, thereby enabling cost reduction and size reduction.

[0049] FIG. 10 is an explanatory diagram of a form in which the overhead line is switched. In FIG. 10, overhead wires 403 are hung on poles (electric poles) 404 installed on the outer edge of field 402 (or within field 402). A plurality of poles 404 can be installed along the outer edge of field 402. The overhead wires 403 can also be configured to be detachably attached to the poles 404. Therefore, the overhead wires 403 can switch between poles 404 supported by a drone 406, which is an example of an unmanned aerial vehicle. Therefore, information can be transmitted and received between the tractor 1 and a server 408 via a public line 407, and a signal can be transmitted from the server 408 to the drone 406 according to a planned travel route 409 of the tractor 1 obtained by the information transmission and reception, thereby automatically piloting the drone 406 and re-hanging the overhead wires 403 (switching the supporting poles 404). This extends the period during which power can be supplied from the overhead line 403 while working in the field 402, further reducing concerns about the remaining capacity of each battery 126, 127. Also, it is possible to supply power by switching between one overhead line 403, without having to lay multiple overhead lines 403.

[0050] FIG. 11 is an explanatory diagram of the case where materials are transported between a work vehicle and an unmanned aerial vehicle. If the work machine is a machine that sprays fertilizer, pesticides, chemical solutions, etc., or is a seedling transplanter that transplants seedlings, or is a sowing machine that sows seeds, not only the amount of fertilizer, seedlings, seeds, etc. that can be stored in the storage area of ​​the work machine, but also bags and boxes of replenishment materials may be loaded onto the work vehicle. Once the bags and boxes have been replenished with materials, they become empty bags and boxes, and are stored in the work vehicle until the work is completed. Here, if the field 402 is large and an attempt is made to work the entire area in one operation, a large amount of materials will need to be loaded, and space will also need to be reserved within the work vehicle for the empty bags and boxes. Here, when using the drone 406 shown in FIG. 10, as shown in FIG. 11, materials can be transported from outside the field 402 to the work vehicle (tractor 1), or empty boxes and the like can be transported from the work vehicle to outside the field 402. This eliminates the need to frequently interrupt work to replenish materials, even if the field 402 is large, and requires less space to store the empty boxes and the like. Also, storing a large number of empty boxes has been problematic in that it takes time and effort to unload them, but by transporting them using the drone 406 while work is in progress, work time can be reduced. Furthermore, while working with a large number of empty boxes loaded on the vehicle reduces the fuel efficiency of the work vehicle by the weight of the empty boxes, using the drone 406 to transport them is expected to improve the fuel efficiency of the work vehicle.

[0051] It is desirable that the drone 406 be equipped with a GNSS, a camera, etc., and configured to move automatically between a marker attached to the work vehicle (such as the ceiling of the cabin) and a marker installed at the position of the work assistant outside the field 402. At this time, a basket 411 for temporarily storing empty boxes, etc., is installed at a specific position relative to the marker on the work vehicle side, and the drone 406 can pick up and transport the basket 411 by catching the hook 411a of the basket 411 with the drone 406. The method of picking up the basket 411 is not limited to the hook 411a. For example, it is also possible to provide a permanent magnet on the basket 411 and an electromagnet on the drone 406 side, and then attract / detach the basket 411 by operating / deactivating the electromagnet.

[0052] FIG. 12 is a perspective view of a diesel engine according to another embodiment. FIG. 13 is an explanatory diagram of a state in which the harness stay is removed from the state of FIG. FIG. 14 is an explanatory diagram of the harness stay. FIG. 15 is an explanatory diagram of the state in which the DPF and resonator have been removed from the state shown in FIG. Figure 16 is an explanatory diagram of the resonator fixing stay, where Figure 16(A) is an oblique view of the resonator fixing stay, Figure 16(B) is a side view of the stay, and Figure 16(C) is an explanatory diagram of the state in which a coupler has been assembled from the state in Figure 16(B).

[0053] 12, as another embodiment, a diesel engine E' can be used as the engine E of the tractor 1. In the diesel engine E', a DPF (Diesel Particulate Filter) 151, which serves as an example of a purification device, is disposed on the front side of the upper part of the engine body 100. The DPF 151 functions as a filter that collects and purifies particulates in the exhaust gas as the exhaust gas from the engine body 100 passes through it. 12, 13 and 15, a DPF 151 according to the embodiment is fixedly supported by a DPF bracket 152 supported on the upper part of the engine body 100. As shown in FIG.

[0054] Furthermore, a resonator 153, which is an example of an intake noise reduction device, is disposed behind the DPF 151. The resonator 153 is disposed on an intake passage to the engine body 100, and has the function of reducing intake noise. 12, 13, and 15, the resonator 153 is fixedly supported by a resonator fixing stay 154. In FIG. 16, the resonator fixing stay 154 has a plate-shaped main body 154a and a first fixing portion 154b that extends forward from the main body 154a and is screwed to the DPF bracket 152. A second fixing portion 154c that extends downward and is screwed to a cylinder head (not shown) of the engine body 100 is formed at the left end of the main body 154a. A third fixing portion 154d that extends downward and is screwed to an adjustment plate (not shown) supported by the engine body 100 is formed at the right rear end of the main body 154a. Therefore, the resonator fixing stay 154 is stably fixed to the engine body 100 at three points, and the position of the resonator 153 is also stable.

[0055] The rear end of the main body 154a is formed with a harness support plate 154e extending diagonally upward and rearward, and a coupler fixing portion 154f provided at the upper end of the harness support plate 154e. A harness tie 154g is supported on the rear surface of the harness support plate 154e. The harness tie 154g is made of a deformable wire-like member, and is deformed so as to wrap around the harness 155, thereby fixing the harness 155. A coupler 155a supported at the tip of the harness 155 is screwed to the coupler fixing portion 154f. Therefore, the position of the harness 155 is fixed by the harness tie 154g, and the position of the coupler 155a can also be stabilized.

[0056] 12, a harness stay 156, which is an example of a harness fixing member and an example of a heat shielding member, is disposed between the resonator 153 and the DPF 151. In FIG. 14, the harness stay 156 has a plate-shaped stay portion 156a disposed above the resonator 153 and a plate-shaped heat shielding portion 156b disposed in a state inserted into the gap between the resonator 153 and the DPF 151. Two fixing holes 156c are formed in the stay portion 156a and are screwed to the resonator 153. In addition, a harness clip 156d is supported on the upper surface of the stay portion 156a to support wiring (harness, not shown) routed toward a sensor (not shown).

[0057] The DPF 151 is prone to temperature rise due to the high-temperature exhaust gas passing through it, and if the resonator 153 heats up due to radiant heat from the DPF 151, there is a risk that the amount of intake air will decrease due to thermal expansion of the resonator 153 and the air. In response to this, by providing a harness stay 156 with a heat shield 156b, the temperature rise of the resonator 153 is suppressed, and the decrease in the amount of intake air is suppressed. In addition, the harness stay 156 is provided with a harness clip 156d, which makes it possible to secure a place to fix the harness.

[0058] Figure 17 is an explanatory diagram of the resonator, where Figure 17(A) is an oblique view, Figure 17(B) is a view from the direction of arrow XVIIB in Figure 17(A), Figure 17(C) is a view from the direction of arrow XVIIC in Figure 17(A), and Figure 17(D) is a view from the direction of arrow XVIID in Figure 17(A). Figure 18 is a cross-sectional view of the resonator in Figure 17, where Figure 18(A) is a cross-sectional view taken along line XVIIIA-XVIIIA in Figure 17(B), Figure 18(B) is a cross-sectional view taken along line XVIIIB-XVIIIB in Figure 17(C), Figure 18(C) is a cross-sectional view taken along line XVIIIC-XVIIIC in Figure 17(D), and Figure 18(D) is a cross-sectional view taken along line XVIIID-XVIIID in Figure 17(D). 17 and 18, the resonator 153 has an intake inlet 161 at the right end and an intake outlet 162 at the left end. The intake inlet 161 and the intake outlet 162 are connected by an intake duct 163. A resonator volume 164 formed by a space is formed below the intake duct 163. A connecting passage 166 connects the left side of the intake inlet 161 and the left part (downstream part) of the intake duct 163.

[0059] A blow-by gas passage 167 connects the rear side of the intake outlet 162 to the left part (downstream part) of the intake duct 163. In this embodiment, the joining part of the connecting passage 166 and the intake duct 163 is disposed upstream of the joining part of the blow-by gas passage 167 and the intake duct 163. The connecting passage 166 joins the intake duct 163 from above, whereas the blow-by gas passage 167 joins the intake duct 163 from behind. The blow-by gas passage 167 is connected to the engine body 100 by a hose (not shown), and allows blow-by gas (unburned gas) generated during combustion in the engine body 100 to pass through.

[0060] The resonator 153 shown in Figures 17 and 18 is, as an example, integrally molded by casting, and the sand removal hole 168 at the upper end is filled with a sealing cap. In conventional configurations, the resonator volume section, connecting passage, intake duct, and blow-by gas passage are configured as separate parts, which requires a large space for installation and increases the number of parts, leading to high costs. In contrast, the resonator 153 of this embodiment has the resonator volume section 164, connecting passage 166, intake duct 163, and blow-by gas passage 167 formed integrally, allowing for space savings, a reduction in the number of parts, and cost reductions. Furthermore, in this embodiment, the midstream and downstream portions of intake duct 163 and DPF 151 are arranged in parallel, which makes it possible to save space compared to a case where they are arranged perpendicular to each other.

[0061] 19A and 19B are explanatory diagrams of an oil filler cap for engine oil according to an embodiment, where FIG. 19A is an explanatory diagram for when the internal engine pressure is low, and FIG. 19B is an explanatory diagram for when the internal engine pressure is high. In FIG. 19, an oil filler cap 172 for opening and closing an engine oil filler opening 171 is attached to an engine oil filler opening 171 of an engine E. The oil filler cap 172 in FIG. 19 has a cap main body 172a with a threaded portion 172b at the bottom and a knob portion 172c at the top that an operator grips when turning the oil filler cap 172. A relief valve 173 is supported in the center of the oil filler cap 172. The relief valve 173 has an outside air port 173a that communicates with the outside air and an opening 173b that communicates with the engine oil tank. A piston 173c is supported between the outside air port 173a and the opening 173b so as to be movable between a position that blocks the outside air port 173a (see FIG. 19A) and a position that opens the outside air port 173a (see FIG. 19B). The piston 173c is pushed by a spring 173d toward a position where it closes the outside air port 173a.

[0062] Therefore, when the internal pressure of the engine E is low, the force of the spring 173d closes the outside air port 173a as shown in Figure 19(A), and the leakage of vaporized engine oil inside is suppressed. When the internal pressure of the engine E increases, the internal pressure pushes the piston 173c, opening the outside air port 173a as shown in Figure 19(B), and the engine oil passage is opened to the outside air, making it possible to release the internal pressure of the engine to the outside. For example, if the blow-by gas passage freezes and is blocked in winter, etc., and the internal pressure of the engine E increases, oil leakage and damage to parts may occur. However, the oil filler cap 172 of the embodiment can suppress an increase in the internal pressure of the engine E, thereby preventing damage to the engine E. Furthermore, even with existing tractors 1, freezing countermeasures can be implemented simply by replacing the oil filler cap 172, making it easy to adapt to cold climate specifications.

[0063] (Example of change) The work vehicle of the present invention is not limited to a tractor, but can also be applied to various work vehicles equipped with work implements such as seedling transplanters and chemical spraying vehicles. Furthermore, although a riding tractor has been exemplified, the present invention is not limited to this and can also be applied to an autonomously traveling work vehicle. [Explanation of symbols]

[0064] 1a...Traveling vehicle body, 3...wheels, 18...Work equipment, 102... Generator, third electric motor, 124R, 124L...first electric motor, 126...electric storage unit, 129...second electric motor, 300...control unit, 401...Electrified part, 402...field, 403... overhead lines, 404...Strut, 406...Unmanned aerial vehicle, E...internal combustion engine, W1: Amount of stored electricity Wa...first threshold, Wb: second threshold, Wc...Third threshold.

Claims

1. a traveling vehicle body (1a) having wheels (3); an internal combustion engine (E) that burns fuel to generate power to drive the wheels (3); a first electric motor (124R, 124L) that generates power to drive the wheels (3) when power is supplied; a generator (102) capable of generating electricity based on the drive of the internal combustion engine (E); a work machine (18) provided on the traveling vehicle body (1a) and performing work on a farm field; a second electric motor (129) for driving the working machine (18); a power storage unit (126) capable of storing the electric power generated by the generator (102), the power storage unit (126) supplying electric power to the second electric motor (129) when the working machine (18) is in operation, and supplying electric power to the first electric motors (124R, 124L) when the wheels (3) are driven by the first electric motors (124R, 124L); the generator (102) functioning as a third electric motor (102) that generates power to drive the wheels (3) when supplied with electricity; A control unit (300) that drives the wheels (3) with the internal combustion engine (E), the first electric motors (124R, 124L), and the third electric motor (102) when the amount of stored electricity (W1) in the electricity storage unit (126) reaches a predetermined first threshold (Wa), and that drives the wheels (3) with the third electric motor (102) and the internal combustion engine (E) when the amount of stored electricity (W1) in the electricity storage unit (126) reaches a second threshold (Wb) that is smaller than the first threshold (Wa). the control unit (300) drives the wheels (3) with the first electric motor (124R, 124L) and the internal combustion engine (E), and when the amount of electricity stored (W1) in the electricity storage unit (126) reaches a third threshold (Wc) that is smaller than the second threshold (Wb), drives the wheels (3) with the first electric motor (124R, 124L) and the internal combustion engine (E), and when the amount of electricity stored (W1) in the electricity storage unit (126) does not reach the third threshold (Wc), drives the wheels (3) with the internal combustion engine (E); A work vehicle comprising:

2. the control unit (300) causing the generator (102) to generate electricity and store it in the electricity storage unit (126) when the amount of electricity stored (W1) in the electricity storage unit (126) does not reach the second threshold (Wb); 2. The work vehicle according to claim 1, further comprising:

3. When the rotational speed of the internal combustion engine (E) reaches a predetermined rotational speed, the power generation load of the generator (102) is increased.

2. The work vehicle according to claim 1.

4. an electric current supply unit (401) that is in contact with an electric powered overhead line (403) arranged across a farm field (402) and is capable of conducting electricity with the electric powered overhead line (403); The storage unit (126) is capable of storing electricity from the overhead line (403) via the current-carrying unit (401); 2. The work vehicle according to claim 1, further comprising:

5. 5. The work vehicle according to claim 4, wherein power can be supplied from the overhead line (403) supported on any one of a plurality of supports (404) provided in the field (402), The overhead wire (403) is re-hung by an unmanned aerial vehicle (406) on the support (404) according to the travel route of the work vehicle.

5. The work vehicle according to claim 4.

Images